Issue:
Thousands of workers in Ontario are exposed to hexavalent chromium or Cr(VI) to varying degrees in industrial settings including steel mills, welding shops, electroplating and painting industries. Adverse health effects associated with inhalation of Cr(VI) include lung cancer and non-malignant respiratory effects, asthma and bronchitis. Currently, “total dust” samples are collected to measure Cr(VI) exposures. “Total dust” samplers do not capture particle sizes greater than 30-40 microns in mean diameter which are believed to contribute to non-maliganant respiratory effects. A more appropriate sampling method for Cr(VI) exposure is to collect particles up to 100 microns in diameter using an inhalable sampler.
Objectives:
The goal of this study is to determine workplace Cr(VI) exposures by collecting size-selective samples (i.e., total, respirable and inhalable samples) and to identify the most appropriate sample collection technique. The particle size distribution and the Cr(VI) contents of dusts and aerosols will be determined in the steelmaking and welding industries. The objectives of the research study are:
1. to collect size-selective air particulate samples in various industries and to characterize the particle size distributions and Cr(VI) contents within the size fractions of these samples,
2. to evaluate the Cr(VI) exposure levels in different work environments associated with each particle size range and to determine which is the most suitable sampling and analytical method for each work environment,
3. to compare these exposures to the Ontario and OSHA occupational exposure limits, the proposed NIOSH REL and to the levels in the health impact assessments in the literature.
Anticipated Results:
This research study will quantify workplace exposures to Cr(VI) in the steelmaking and welding industries, employing more comprehensive, exposure-relevant sampling techniques and more sensitive analytical methodology.
Investigators:
Brian E. McCarry, Lorraine Shaw, Dave K. Verma (McMaster University), Murray M. Finkelstein (Mt. Sinai Hospital)
